1. Field of the Invention
The preferred embodiment of the invention is directed to self-loading rock and aggregate separators using a combination of gravity, agitation and centrifugal force for separation. The apparatus acquires a load of aggregate (a mixture of various materials such as sand, gravel, rock, etc.), makes selected piles of different size particles and dumps the remaining mixture in still another pile. The apparatus is adjustable for successively separating a selected size particle, e.g., less than one inch, one inch, three inches, twelve inches, etc. Separation of the different materials is obtained by agitation and by forcing particles out between relatively moving portions of the apparatus by means of centrifugal forces and gravity.
2. Description of Related Art
Prior art devices include a rake or fork separator attached to a backhoe or a bulldozer. These devices do not produce piles of different size particles and do not do a good job of separating particles because the smaller particles usually are not separated from the larger particles. In these devices, separation is dependent upon gravity alone and not by the use of vibration, agitation or centrifugal forces.
Another type of separator, known as a Grizzly separator, consists of slanted rails in which small particles fall between the rails. Large particles that cannot pass between the rails, roll off by the force of gravity. This device is also not adjustable and depends solely upon gravity, and does not achieve separation by vibration, agitation or centrifugal forces. This separator is heavy and does not do a good job of separating the mixture. Usually the separation of particles is in two groups, that is, the particles that fall between the rails and the particles that roll off the rails.
Still another type of separator, known as a rotary drum screen separator, requires a feeder. The mixture is rotated inside the drum where the mixture is screened for the smaller particles first. The slant of the drum enables larger particles to be screened at the end of the drum. The remaining large particles are then discharged. This device requires a feeder and the system is very heavy, weighing between 10-50 tons.
Another prior art device comprises a vibrating screen separator which separates the particles by different size screens arranged in multiple layers. Particles smaller than the screen size fall through the screen and onto the next size screen while particles that are too large to pass through the screen are vibrated off the screen. This device may require a feeder, requires a lot of power to run and weighs between 5-10 tons. Wet materials may cause problems in the separation process.
The purpose of the instant invention is to separate dirt and sand from rock or concrete that are mixed together, i.e., the separation of an aggregate mixture into piles according to a selected maximum size of the individual components of the aggregate. The piles may be separately placed on the ground or may be individually and sequentially placed on a conveyor belt. Plastic and like material may also be separated from dirt and sand according to size. The instant invention enables better separation of a mixture because agitation of the material is continuous, and may be repeated over and over again separating the mixture by agitation, gravity and centrifugal forces, and does not depend on a one-pass gravity procedure as in the prior art. The material to be separated is thrown out by centrifugal force from between a gap formed between a rotating disk and a stationary portion of a machine such as the bucket of a backhoe. A portion of the bottom of the bucket is removed and the rotating disk covers the cutout with a space therebetween. Required power is less since the mixture is not crushed and does not require a feeder. Wet materials may also be separated. After separation, the large particles may be used by placing them on a sand or clay bed to form a base, such as for a road bed. Once the base for the road is laid down, the smaller particles may be placed on top so that the top surface can be made smooth. The invention can be attached to a track or rubber-tired vehicle such as a front loader, farm tractor or other such equipment. The invention may also be used in a fixed installation or in conjunction with an overhead crane.
For purposes of illustrating the invention, a backhoe having a bucket with the bottom cut out may be utilized. An adjustable hydraulically-driven rotating disk attaches to the bucket and covers the cut out portion of the bottom of the bucket, the combination having a gap, or a selected spaced-apart relationship, between the stationary bucket and the rotating disk. The disk is driven by a combination hydraulic motor/transmission system the latter being well known in the art. It will also be appreciated that the disk may be mechanically driven. In the preferred embodiment, the bucket is self-loading and may be tilted back while the disk is rotating, thereby causing the mixture to be agitated by the disk and with the other particles in the bucket. Particles smaller than the selected gap distance, e.g., one inch in diameter, are thrown out, through the gap between the edge of the disk and the cutout portion of the bucket, by centrifugal force. After the particles of selected size have been separated into a pile, the gap may be increased and the bucket re-positioned so as to pile the next larger size particles of, say, one to three inches, etc. in a separate pile by repeating the process. This process is repeated until the gap has been increased to its maximum size. The pieces of rock or material larger than the selected size of the gap remain in the bucket and may be dumped out in still another pile by tilting the bucket and throwing the larger particles out of the bucket. Then, the process may be repeated by reloading the bucket with another load of a mixture, with the sand and dirt therein being separated to their respective piles as described above. Sometimes the disk may stall, due to wet material or particles hanging up in the gap, so the hydraulic motor/transmission system can be reversed to free the disk. This separator is not a rock crusher like a cone crusher.